Fastening for canvas aprons employed in certain description of photoprinting-frames.



No. 683,040. Patented Sept. 24, I90l. J. HALDEN.

FASTENING FOR CANVAS APRONS EMPLOYED IN CERTAIN DESCRIPTIONS 0FPHUTOPRINTING FRAIES.

Application fllod nu. 2a, 1001.

m 683,040. Patented sm. 24, mm. J. HALDEN. FASTENING FOR CANVAS APRONSEMPLOYED IN CERTAIN DESCRIPTIONS 0F PHOTOPRINTING FRAMES. A

(Application filed Feb. 25, 1001. (Jlo Model.)

2 Sheen-Sheet 2.

W/TNESSES. INVENTOR.

rm: nouns PEKRS no. PuoTu! mm, wAsnmr-mu. u c.

UNITED STATES PATENT OFFICE.

JOSEPH IIALDEN, OF MANCHESTER, ENGLAND.

FASTENING FOR CANVAS APRONS EMPLOYED IN CERTAIN DESCRIPTIONS OFPHOTOPRINTING-FRAMES.

SPECIFICATION forming part of Letters Patent No. 683,040, datedSeptember 24, 1901.

Application filed February 25, 1901. Serial No. 48,845. (No model.)

To coZZ 10700112, it may concern:

Be it known that I, JOSEPH HALDEN, a subject of the King of GreatBritain and Ireland, residing at 8 Albert Square, Manchester, in thecounty of Lancaster, England, have invented a new and Improved Fasteningfor Canvas or Like Aprons Employed in Certain Descriptions ofPhotoprinting Apparatus, (in respect whereof I have applied for a patentin Great Britain to bear date January 10, 1901, No. 703,) of which thefollowing is a specification.

This invention relates to photoprinting apparatus of the characterwherein a drum or cylinder formed of transparent material is mounted ontrunnions, so as to be capable of rotation about its transverse axis, alamp or other source of light entering the interior of the drum, whilethe drawings to be reproduced, together with the sensitive paper, aresecured upon the exterior surface thereof.

My improvements have special reference to means for securing the canvasaprons or jackets which serve to retain the tracings, together with thesensitized paper, upon the exterior surface of the glass or othertransparent drum or cylinder about which they are arranged whileundergoing reproduction.

In the accompanying drawings, Figure 1 is a view illustratingphotoprinting apparatus of the character to which my improvements areapplicable. Fig. 2 is a transverse section, and Fig. 3 a plan, of thedrum or cylinder drawn to a larger scale. Fig. 4 is an elevation of aportion of a spindle furnished with hooks or fingers for engaging withthe rod or lath in the edge of the apron, Figs. 5 and 6 being transversesections showin different forms of hooks or fingers. Fig. 71s anelevation of a spindle or bar formed with cranked portions; and Figs. 8and 9 are transverse sections, respectively, of a shaped bar and abuilt-up bar, each having a longitudinal fin.

In order that my improvements may be properly understood, it will benecessary to explain the general construction of the apparatusillustrated in Fig. 1 and the mode of working the same.

The apparatus comprises a cylindrical structure formed of two semi orapproxi- Inately semi cylindrical portions a a of glass or othersuitable transparent material/the extremities of each portionaa beingmounted in heads I) Z), whereof the grooves are furnished withcaoutchouc or other yielding packing. The heads I) I) are connectedtogether by pairs of bars or tubes 0 0, arranged on each side of thestructure adjacent to the opening which occurs between the longitudinaledges of the transparent portions a a. The cylindrical structure ismounted in a frame d by means of trunnions, one of which, e, carries aplate f, formed with holes for the insertion of a retaining'pin andadapted to register with holes formed in the framing d. The electric-arclamp g, which is adapted for being raised and lowered according to therequirements of the work under reproduction, is admitted into thecylinder through the central opening in whichever of the heads I) b isuppermost.

In working the apparatus, assuming a drawing prepared on tracing-paperis to be reproduced by the ferricyanid or like photographic process andthat the cylinder is in the position indicated by broken lines in Fig.1, the tracing is laid upon the upper surface of the cylinder and thesensitized paper placed upon the rear side of the tracing, a canvas orother apron h, secured about the cylinder by means of clips, serving toretain the tracing and the sensitized paper in position during theprocess of printing. By turning the cylinder the opposite side may besimilarly utilized. The cylinder thus equipped is then turned through anangle of ninety degrees, a retaining-pin being inserted through one ofthe holes in the plate f and passed into the coinciding hole in theframing. The cylinder is hereby retained in the position indicated infull lines in Fig. 1. The lamp is now lowered into the cylinder,whereupon the process of reproduction commences.

In securing the canvas apron in position according to my improved methodI employ spindles t, which extend the entire length of the cylinder a aand which are rotatably mounted in the heads I) I), wherein the cylinderterminates. Each spindle is furnished at intervals with hooks or fingersi, which engage with a rod or lath h, wherewith the edge of the apronhis furnished. Each spin (110 2' is provided at one end or at each endwith a ratchet 7c and releasable pawl 70, which operate to hold thespindle i in the position to which it may have been rotated, and thus tomaintain the apron 72 at the required tenslon.

Instead of furnishing the spindle with hooks or fingers 2', as shown inthe detached views, Figs. 5 and 6, the portion thereof which engageswith the lath or rod h in the edge of the apron may be continuousthroughout the length of the spindle, the engagement being under suchcircumstances continuous instead of intermittent.

The spindle may consist of a rod upon which the hooks or fingers aremounted and secured, as shown in Fig. 4, or it may consist of a barformed with one or more cranked portions 2' Figs. 1, 2, and 7, or it mayconsist of a bar 1'", formed or provided with a longitudinal fin 4?,which projects laterally and engages with the lath or rod h in the edgeof the apron h. It will be observed that at suitable distances along thelath h hooks or bent plates h are attached for affording a hold for thefin z' A shaped bar or spindle of the section last referred to may bebuilt up ofa plate i secured between two half-round or other suitablestilfening-bars 1' i the plate i projecting on one side and forming arib adapted for engaging with the lath or rod 71/, as shown in Fig. 9. Zis a detachable handle wherewith either of the spindles 1 may berotated. I

With a view to enabling the tension of the apron h to equalize itselfits back edge may be provided with a rod 7L and be attached by means oftension-springs h to the adjacent bars 0, pertaining to the heads b b.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. In photoprinting apparatus, the hereindescribed means for securingthecanvas aprons in position upon the printing-cylinder, consisting ofspindles rotatably mounted in the heads pertaining to the cylinder andhaving catches thereon to engage with the edges of the apron.

2. For securing the canvas aprons in position in photoprintingapparatus, a spindle, extending along the printing-cylinden rotatablymounted in the heads of the 1atter,and having laterally-formedprojections adapted, upon the spindle being rotated, to engage the rodwherewith the apron is furnished, and to hold the apron in tension,substantially as herein described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

. JOSEPH HALDEN.

Witnesses:

F. J. RAPSON, EDWD. BLUNDEN.

